JPS613658A - Masking method for soldering of capacitor element - Google Patents

Abstract

PURPOSE:To obtain a masking effect with high reliability by constituting a self- adhesive tape of a light-transmissible substrate and a photosetting self-adhesive agent layer thereon and irradiating light on two sheets of the self-adhesive tapes prior to stripping of two sheets of the self-adhesive tapes after soldering. CONSTITUTION:The self-adhesive tape in the conventional masking method for capacitor elements is constituted of the light-transmittable substrate and the photosetting self-adhesive agent layer provided on the substrate thereof. PVC, PE terephthalate, PE, etc. are used for the light-transmissible substrate. Any photo setting self-adhesive agent layer whith has normally tack and cures to have the decreased adhesive strength to the condenser elements when irradiated with light is satisfactory. The light is irradiated on two sheets of the self-adhesive tapes prior to stripping of two sheets of the self-adhesive tapes after soldering.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a soldering masking method for a capacitor element, and more particularly, the present invention relates to a soldering masking method for a capacitor element, and more particularly, the present invention relates to a method for soldering and masking a capacitor element, and more specifically, the present invention relates to a method for soldering and masking a capacitor element, and more specifically, the present invention relates to a soldering masking method for a capacitor element. The present invention relates to a masking method for preventing solder from adhering to surfaces of devices that do not require soldering.

[Background Art] Conventionally, in this type of masking method, a plurality of capacitor elements are placed between two adhesive tapes with their adhesive layers facing each other. A capacitor element connected body is formed by arranging the two adhesive tapes so as to be exposed at the ends in the width direction and closely adhering the two adhesive tapes to the surfaces of the respective capacitor elements that do not require soldering, and forming a capacitor element connected body. There is a known method in which the two adhesive tapes are peeled off after soldering is performed on the surface of each capacitor element that requires soldering.

In addition, two heat-sensitive adhesive tapes can be used instead of the two adhesive tapes mentioned above, and each A method similar to the above masking method except that the capacitor element is heated is also known.

In any of the above methods, each capacitor element after soldering is recovered by peeling off from the masking tape due to its own weight as the two adhesive tapes or the two heat-sensitive adhesive tapes are peeled off from each other. It is designed to be done.

However, depending on the adhesive strength of the masking tape to each capacitor element, the capacitor element may not peel off due to its own weight alone and may remain adhered to the masking tape, or the capacitor element may be damaged when the masking tape is peeled off. There are cases where the capacitor elements cannot be recovered efficiently and reliably, as they may be damaged.

- On the other hand, attempts have been made to reduce the adhesive strength so that the capacitor elements can be recovered without the problems described above, but if the adhesive strength is reduced due to peeling, the capacitor elements may be connected before soldering. Due to the load of the vehicle while running and the weight of each capacitor element, the masking tape and the surface of each capacitor element that does not require soldering separates, creating a gap, and molten solder infiltrates into this gap during soldering. Therefore, the masking effect may be insufficient.

That is, the adhesive force of the masking tape to the capacitor element is strong enough to firmly adhere to the surface of the element that does not require soldering during soldering work, and to exert a sufficient masking effect, and after soldering. The size must be adjusted so that it can be easily peeled off from the capacitor element, but it is difficult to adjust the adhesive strength of ordinary adhesive tape or heat-sensitive adhesive tape in this way, so masking The current situation is that there is a need for the development of a masking method that satisfies both the reliability of the effect and the reliability of the recovery operation of capacitor elements after soldering.

[Purpose of the invention]

The present invention provides a soldering masking method for capacitor elements that has a highly reliable masking effect during soldering, and that allows recovery of capacitor elements and elements after soldering with good workability and without damaging the capacitor elements. The purpose is to provide.

[Summary of the invention]

As a result of intensive studies to achieve the above object, the inventors discovered that, in the masking method using the conventional adhesive tape, a photocurable adhesive was used on a light-transmitting support instead of the conventional adhesive tape. If you use an adhesive tape with layers, even if the adhesive strength of the adhesive tape to the capacitor element is set to a level that can exert a sufficient masking effect on the element, the adhesive tape can be peeled off after soldering. By irradiating this adhesive tape with light before applying light, the photocurable adhesive layer of this tape is cured, reducing the amount of work due to plastic flow of the adhesive layer and reducing the adhesive force to the capacitor element. The present inventors have discovered that it is possible to reliably recover capacitor elements with good workability and without damage to capacitor elements, leading to the creation of this invention.

That is, in this invention, a plurality of capacitor elements are placed between two adhesive tapes with their adhesive layers facing each other, and the surface to which each capacitor element needs to be soldered is the width of the two adhesive tapes. A capacitor element assembly is formed by arranging the two adhesive tapes so as to be exposed at the directional ends and closely adhering the two adhesive tapes to the surfaces that do not require soldering of each of the capacitor elements, and soldering each capacitor element in this assembly. In a soldering masking method for a capacitor element, in which the above two adhesive tapes are peeled off after soldering is performed on a surface that requires soldering, the above adhesive tape is attached to a light-transmitting support and this support is provided. A soldering masking method for a capacitor element, characterized in that the two adhesive tapes are irradiated with light after the soldering and before the two adhesive tapes are peeled off. It is something.

[Effects of the Invention] According to the masking method of the present invention, the adhesive strength of the adhesive tape, which is a masking tape, can be made large enough without considering the workability of recovering capacitor elements after soldering. Sometimes, this adhesive tape will adhere firmly to the side of the capacitor element that does not require soldering, so that no solder will adhere to this side.

On the other hand, after soldering, the adhesive tape is irradiated with light to harden the photocurable adhesive layer of the adhesive tape, which reduces the amount of work caused by the plastic flow of the adhesive layer, making the soldering process unnecessary. Adhesive strength to surfaces that are not stained will be significantly reduced.

Therefore, when the adhesive tape is peeled off, the capacitor element easily peels off due to its own weight or fluid pressure such as wind pressure and is recovered, and the risk of damage to the capacitor element during the peeling off is avoided.

As described above, according to the masking method of the present invention, the masking effect during soldering is highly reliable, and the capacitor elements can be recovered after soldering with good workability and without damaging the capacitor elements. be able to.

[Structure of the Invention] The adhesive tape used in the masking method of the present invention has a structure in which a photocurable adhesive layer is provided on a light-transmitting support. Examples of the light-transmissive support include plastic films such as polyvinyl chloride, polyethylene terephthalate, polyethylene, and polypropylene, and paper.

The thickness of this support is usually about 10 to 300 pn.

The above-mentioned photocurable adhesive layer is not particularly limited as long as it is adhesive in normal state and hardens upon light irradiation to reduce the adhesive strength to the capacitor element, but it has the property of curing upon light irradiation and forming a three-dimensional network. Those having the following are particularly preferable because the adhesive strength is significantly reduced by light irradiation.

The photocurable adhesive layer, which has the property of curing and forming a three-dimensional network upon irradiation with light, is made of a rubber-based or acrylic polymer used as a base polymer for ordinary rubber-based or acrylic-based adhesives. A low molecular weight compound having at least two photopolymerizable carbon-carbon double bonds (hereinafter referred to as a photopolymerizable monomer), a photopolymerization initiator, and as necessary to increase the cohesive force of the photocurable adhesive layer. It is formed using a photocurable adhesive composition containing a silica filler and a crosslinking agent.

Examples of the above-mentioned rubber-based polymers include natural rubber and various synthetic rubbers. In addition, the above acrylic polymers include poly(meth)acrylic acid alkyl ester, (meth)
Examples include copolymers of acrylic acid alkyl esters and other unsaturated monomers that can be copolymerized with the acrylic acid alkyl esters.

The above photopolymerizable monomer usually has a molecular weight of 1
The molecular weight is preferably about 0,000 or less, and more preferably the molecular weight is about 5,000 or less and intramolecular photopolymerizability so that the photocurable adhesive layer can be efficiently formed into a three-dimensional network by light irradiation. It is preferable to use one having 3 to 6 carbon-carbon double bonds.

Such particularly preferred photopolymerizable monomers include:
Examples include trimethylolpropane triacrylate, tetramethylolmethanetetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, and the like. In addition, other photopolymerizable monomers include ■4-butylene glycol diacrylate,
Examples include 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, and commercially available oligoester acrylate.

As the photopolymerizable monomer, one type of the above-mentioned compounds may be used alone or two or more types may be used in combination, and the amount used is usually 100% by weight of the above-mentioned rubber-based or acrylic-based polymer. The range is preferably from 1 to 100 parts by weight. If the amount used is too small, the three-dimensional reticulation of the photocurable adhesive layer by light irradiation will be insufficient, and the degree of decrease in the adhesive force of the adhesive tape to the capacitor element will be reduced, which is not preferable. Furthermore, if the amount used is too large, the photocurable adhesive layer will be significantly plasticized, making it impossible to obtain the adhesive force required during masking, and this is not preferable since there is a risk that the adhesive layer will protrude during masking.

Examples of the above photopolymerization initiators include isopropyl benzoin ether, inphthyl benzoin ether, benzophenone, Michler's ketone, chlorothioxanthone, dodecylthioxanthone, dimethylthioxanthone,
Examples include diethylthioxanthone, acetophenone diethyl ketal, benzyl dimethyl ketal, α-hydroxycyclohexylphenyl ketone, 2-hydroxymethylphenylpropane, etc. If one of these is used alone or in a mixture of two or more, The amount of this photopolymerization initiator to be used is usually 0 to 100 parts by weight of the above-mentioned rubber-based or acrylic-based polymer.
．． The amount is preferably in the range of 1 to 50 parts by weight. If the amount used is too small, the three-dimensional network formation of the photocurable adhesive layer by light irradiation will be insufficient, and the degree of decrease in the adhesive force of the photocurable adhesive layer to the capacitor element will be undesirably low. Moreover, if the amount used is too large, the photopolymerization initiator will remain on the surface of the capacitor element, which is not preferable. Note that, if necessary, an amine compound such as triethylamine, tetraethylpentamine, dimethylaminoethanol, etc. may be used together with this photopolymerization initiator as a photopolymerization accelerator.

Examples of the silica filler used as necessary include finely powdered silica, and examples of the crosslinking agent include polyisocyanate compounds and alkyl etherified melamine.

A photocurable adhesive composition containing the above-mentioned components is coated on a light-transmissive support and heated as necessary to cure the photocurable adhesive composition by light irradiation to form a three-dimensional network. A sticky adhesive layer is formed. The thickness of this photocurable adhesive layer is usually about 5 to 100p.

In addition, this photocurable adhesive layer usually has a 100% modulus (at 20°C) of 5 kg/tyrl or less, a gel fraction of less than 80% by weight as determined by immersion in toluene for 24 hours, and a gel swelling degree of less than 80%. is preferably 10 times or more.

In the method for soldering and masking capacitor elements of the present invention, an adhesive tape comprising the above-mentioned light-transmitting support and a photocurable adhesive layer is used as a masking tape.

In the method of this invention, first, the two adhesive tapes described above are placed with the photocurable adhesive layer side facing each other, and a plurality of capacitor elements are placed between these two adhesive tapes, and each of these capacitor elements is soldered. The two adhesive tapes are arranged so that the required surfaces are exposed at the ends in the width direction of the two adhesive tapes, and the two adhesive tapes are brought into close contact with the surfaces of each of the capacitor elements that do not require soldering to form a capacitor element assembly. form.

FIG. 1 is a perspective view showing an example of this capacitor element assembly. In the same figure, 1,1. -. is a capacitor element, in which surfaces 2, 2°, . ...The larger surface 4a
, 4a, . . . are arranged at predetermined intervals perpendicular to the longitudinal direction of the tape, and the surfaces 4, 4 . . . do not require soldering. ..., the two adhesive tapes 3, 3 are in close contact with each other, covering the surfaces 4, 4° which do not require soldering, and connecting each of the capacitor elements 1, 1°... .

Surfaces 4, 4 of the two adhesive tapes 3, 3 that do not require soldering. The adhesive strength (180° peeling, peeling speed 300 H/min) to ... is usually 500 ~ 500 before irradiation with light.
It is about 800P/15+++m, and the capacitor elements 1, 1. Due to their own weight, these two adhesive tapes 3, 3 are attached to the surfaces 4, 4, which do not require the above-mentioned soldering. It does not peel off from ... and is firmly adhered to the surfaces 4 and 4 degrees that do not require soldering. For this reason, each of the above capacitor elements 1
,1. Surface 2, 2° that requires soldering...
・While performing soldering, the above-mentioned surfaces 4, 4. which do not require soldering. ...Solder does not adhere to the surface.

In the method of the present invention, a capacitor element assembly as described above is formed, and each of the capacitor elements I, 1. Surfaces 2, 2, . . . that require soldering.・
...After soldering, attach the above two pieces of adhesive tape 3
, 3 is irradiated with light, and then both of these adhesive tapes 3, 3 are peeled off to form each capacitor element 1, 1. Collect...

The above soldering is usually performed by metal spraying, and each capacitor element 1, 1. Surfaces 2, 2, . . . that require soldering. ...Soldering is performed continuously.

The above-mentioned light irradiation may be performed using a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, or the like, and usually irradiates light with a wavelength of 180 to 460 nm, for example, for about 3 to 60 seconds using a 12 KW high-pressure mercury lamp. By this light irradiation, the above two adhesive tapes 3,
The photocurable adhesive layer in 3 is cured to form each of the capacitor elements 1, 1. The adhesion force (180° peeling, peeling speed 300 mm, 7 minutes) to surfaces that do not require soldering is usually about 50y/15cm or less. For this reason, for example, when the two adhesive tapes 3, 3 after being irradiated with light are rolled up and peeled off by rerolls 5, 5 as shown in FIG. 2, the soldered capacitor elements I, 1. . . . easily peels off from both the adhesive tapes 3, 3 due to their own weight and is collected in the collection container 6.

In addition, when the photocurable adhesive layer in the adhesive tapes 3 and 3 has the property of being cured by light irradiation and forming a three-dimensional network, the photopolymerizable monomers of the adhesive layer polymerize with each other when irradiated with light. At the same time, radicals are also generated in the rubber-based or acrylic-based polymer, and this polymer reacts with the photopolymerizable monomer, thereby hardening the adhesive layer and forming a three-dimensional network.

Three-dimensional reticulation here usually means that the gel fraction determined by immersing the adhesive layer in toluene for 24 hours is 14 times or more that before light irradiation, and that this gel fraction is 55% by weight or more. It means to become. Further, the pressure-sensitive adhesive layer after irradiation with light preferably has a gel swelling degree of usually 18 times or less, which is determined in the same manner as above.

By creating a three-dimensional network in this way, the cohesive force of the photocurable adhesive layer increases significantly compared to before irradiation with light, and usually 1
00% modulus (20°C) is 20Kg/cd or more. Along with this, the above-mentioned surfaces 4, 4 which do not require soldering. The adhesion force to ... is significantly reduced, and the adhesion force at this time (180° peeling, peeling speed 300++++
+/min) is usually 50 yI 15 mm or less. For this reason, capacitor elements 1, 1. ... can be recovered very easily.

[Examples] Examples of the present invention will be described below. In addition, in the following, parts mean parts by weight.

Example 1 A blended composition consisting of 100 parts of butyl acrylate and 10 parts of acrylic acid was copolymerized in toluene to obtain an acrylic copolymer having a number average molecular weight of 400,000.

To 100 parts of this copolymer were added 0.5 parts of a polyisocyanate compound (product name Coronate, manufactured by Nippon Polyurethane Co., Ltd.), 5 parts of benzophenone, 30 parts of trimethylolpropane acrylate, 20 parts of tetramethylolmethane acrylate, and 1 part of a silica filler. A photocurable adhesive composition was prepared by adding and mixing. This adhesive composition was coated on one side of a 25 μm thick polyester film so that the photocurable adhesive layer had a thickness of 10 μm, and heated at 130° C. for 2 minutes to obtain an adhesive tape.

A capacitor element assembly shown in FIG. 1 was formed using two of these adhesive tapes (width 15+++ m) and 50 capacitor elements (15 mm x 5 mi x 9 mm, size of surface requiring soldering: 5 m 1 x 9+++ m).

Each capacitor element 1, 1 . Surfaces 2, 2, . . . that require soldering. Soldering is done by metal spraying method, and then the above two pieces of adhesive tape 3 are soldered.
, 3, the irradiation distance was 60c using an ultra-high pressure mercury lamp (3KW).
Light was irradiated for 10 seconds as m, and then the two adhesive tapes 3゜3 after the light irradiation were peeled off as shown in Fig. , 3 and was collected, and only one capacitor element 1 was not collected while remaining adhered to the adhesive tape 3.

In addition, recovered capacitor elements 1, 1. . . . are surfaces 2, 2., which require soldering.・Solder is only attached to the surface and no soldering is required 4゜4,・
...No solder adhesion was observed, and no element damage was observed. Furthermore, the capacitor element still adhered to the adhesive tape could be recovered without damaging the element by gently shifting the adhesive surface by hand.

Example 2 100 parts of an acrylic copolymer (the same as in Example 1) was mixed with 0.5 parts of a polyisocyanate compound (coronated as described above).
A photocurable adhesive composition was prepared by adding and mixing 30 parts of trimethylolpropane acrylate, 20 parts of tetramethylolmethane acrylate, 20 parts of benzophenone, and 1 part of a silica-based filler. An adhesive tape was obtained in the same manner as in Example 1.

When 50 capacitor elements were masked and soldered to these capacitor elements using this adhesive tape in the same manner as in Example 1, all of the soldered capacitor elements easily peeled off from the irradiated adhesive tape. and was recovered. In addition, all of the recovered capacitor elements had solder attached only to the surfaces that required soldering, and no solder was observed on the surfaces that did not require soldering, and no damage to the elements was observed.

Example 3 100 parts of an acrylic copolymer (same as Example 1), 5 parts of a polyisocyanate compound (the aforementioned Coronate L), 80 parts of trimethylolpropane acrylate, 20 parts of tetramethylolmethane acrylate, 20 parts of benzophenone, and silica A photocurable adhesive composition was prepared by adding and mixing 1 part of a filler, and this composition was used in Example 1.
Adhesive tape was obtained in the same manner.

Fifty capacitor elements were masked using this adhesive tape in the same manner as in Example 1, and these capacitor elements were soldered. When collected after soldering, the adhesive tape had all of the capacitor elements irradiated with light. It peeled off easily and was recovered. In addition, all of the recovered capacitor elements had solder attached only to the surfaces that required soldering, and no solder was observed on the surfaces that did not require soldering, nor was there any damage to the elements. .

Example 4 100 parts of an acrylic copolymer (same as in Example 1) and 0.0 parts of a polyisocyanate compound (Coronate L described above) were added.
5 parts, benzophenone 5 parts, polyfunctional oligoester acrylate (trade name: Aronix M, manufactured by Toagosei Chemical Industry Co., Ltd.)
A photocurable adhesive composition was prepared by adding and mixing 50 parts of 8030) and 1 part of a silica filler, and an adhesive tape was prepared in the same manner as in Example 1 using this composition.

Fifty capacitor elements were masked using this adhesive tape in the same manner as in Example 1, and these capacitor elements were soldered. When collected after soldering, the capacitor elements were easily removed from the light-irradiated adhesive tape. There was only one capacitor element that peeled off and was recovered, and was not recovered while remaining adhered to the adhesive tape.

In addition, in all of the recovered 1st capacitor elements, solder was only attached to the surfaces that required soldering, and no solder was observed on the surfaces that did not require soldering, and no damage to the elements was observed. . Furthermore, the capacitor element still adhered to the adhesive tape could be recovered without damaging the element by gently shifting the adhesive surface by hand.

Comparative Example Example 1 Using a heat-sensitive adhesive tape (acrylic rubber adhesive, adhesive temperature 100°C) instead of adhesive tape
A capacitor element connection body similar to the above was formed. After soldering the surfaces of each capacitor element in this connected body that require soldering by a metal spraying method, Example 1
When the heat-sensitive adhesive tape was peeled off in the same manner as above, 3 of the 50 capacitor elements remained attached to the adhesive tape and were not recovered, and the rest were weighed down by their own weight.
It fell off and was recovered. All of the recovered capacitor elements had solder attached only to the surfaces that required soldering, and no solder was observed to adhere to the surfaces that did not require soldering. However, some of the recovered items and the recovered devices that were removed by hand while still attached to the tape were found to have damage on the surface of the devices due to the strong adhesive force of the tape.

Test Example Adhesive strength of the adhesive tapes of Examples 1 to 4 above to polyester film (180° peeling, peeling speed 300 mm/
minutes) were measured before and after light irradiation. The adhesive strength before light irradiation was measured after affixing the adhesive tape to the polyester film and leaving it at room temperature for 1 hour, and after leaving it in a dryer at 80°C for 1 hour. The adhesive strength was measured after attaching the adhesive tape to the polyester film, leaving it at room temperature for 1 hour, and then irradiating the old adhesive tape with light for 10 seconds using an ultra-high pressure mercury lamp (3Kl) at an irradiation distance of 60 cm. At the same time, the adhesive tape was attached to the polyester film, left in a dryer at 80°C for 1 hour, and then irradiated with light in the same manner as above, and then measured.

In addition, the adhesive force of the heat-sensitive adhesive tape of the comparative example to the polyester film was measured. This measurement was performed after the adhesive tape was attached to the polyester film at 80°C and left for 1 hour.

These results are shown in the table below.

From the above Examples 1 to 4 and Comparative Example, it is clear that the method of soldering and masking capacitor elements of the present invention provides a highly reliable masking effect during soldering, and that recovery of capacitor elements after soldering is easy. Furthermore, it can be seen that this can be done reliably without damaging the element. In addition, this effect is obtained because the adhesive tape used in the method of this invention has high adhesive strength before irradiation with light, but after irradiation with light, it hardens and the adhesive strength decreases significantly. It is clear from the above test examples that.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an example of a capacitor element assembly formed in the capacitor element soldering masking method of the present invention, and FIG. 2 is a perspective view showing an example of a capacitor element assembly formed in the capacitor element assembly shown in FIG. It is a front view showing the state where it is later collected. 1... Capacitor element, 2... Surface that requires soldering, 3, 3 - Adhesive tape, 4... Surface that does not require soldering

Claims (1)

[Claims] (1) A plurality of capacitor elements are placed between two adhesive tapes with their adhesive layers facing each other, and the surface of each capacitor element that requires soldering is exposed at the widthwise edge of the two adhesive tapes. A capacitor element assembly is formed by arranging the capacitor elements in such a manner that the two adhesive tapes are closely attached to the surfaces of the capacitor elements that do not require soldering, and each capacitor element in this assembly does not require soldering. In the soldering masking method for a capacitor element, in which the two adhesive tapes are peeled off after soldering on the surface to be soldered, the adhesive tape is attached to a light-transmitting support and a photocurable adhesive provided on the support. A method for soldering and masking a capacitor element, characterized in that the two adhesive tapes are irradiated with light after the soldering and before the two adhesive tapes are peeled off.